Saw blade with sanding surface

ABSTRACT

A saw blade includes a very shallow cone shaped side for supporting an abrasive surface to sand smooth a cut surface of a work piece while the surface is being cut by the saw blade. To maintain the finished sanded surface of the cut perpendicular to a specified axis of the work piece, the axis of rotation of the saw blade is tilted to place a radial of the cone shaped abrasive surface orthogonal in three axis to the direction of saw cut being made.

This is a continuation of prior application Ser. No. 08/296,682, filedAug. 26, 1994, now U.S. Pat. No. 5,524,528, for "SAW BLADE WITH SANDINGSURFACE".

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to saw blades and, more particularly, torotary saw blades incorporating an abrasive surface for simultaneouslycutting and finishing the surface of a work piece.

2. Description of Prior Art

Saw blades for use with rotary saws include offset or non-offset teeth.If offset teeth are employed, the kerf is wider than the thickness ofthe saw blade which wastes material but prevents binding between thework piece and the saw blade. The smoothness of the cut surface in thework piece is generally a function of the size of the teeth, theconfiguration of the teeth, and the number of teeth per unit ofcircumference. Generally, a fine toothed rotary saw blade will make amore finished cut than a coarse toothed saw blade. The latter, however,provides a more rapid cut, and is therefore preferable in manyapplications. Depending upon the purpose of the work piece, saw cutsmade therein may have to be sanded smooth or finished by an abrasivetool, such as sandpaper. This step adds to the costs of making the sawcut in terms of additional equipment being required, the costs attendanta workman sanding the cut and costs attendant more time required toconstruct the finished product. If it were possible to eliminate theextra step of sanding the cut surface in the work piece, significantsavings could be realized.

Various attempts have been made to incorporate an abrasive or a sandingelement with a rotary saw blade. Such attempts include the forming ofteeth on a side of a saw blade; if such teeth do not extend laterallybeyond the plane of the cut being made, they cannot serve their purpose.Abrasive elements and sanding disks have been added to a side of a sawblade to perform a finish sanding function commensurate with a saw cutbeing made. Because such abrasive materials, sandpaper, or even teethextending from the side of a saw blade contact the work piece at theperimeter of the abrasive, sandpaper or teeth, the peripheral edgeperforms most of the sanding function. This causes rapid wear due to ahigh concentration of forces present at the perimeter or peripheraledge.

SUMMARY OF THE INVENTION

A rotary saw blade includes a shallow cone shaped surface for supportinga shallow cone of sandpaper, abrasive material or other element capableof performing a sanding function as it passes across a work piece. Byorienting the axis of rotation of the rotary saw blade to place a radialof the sanding surface orthogonal to two axis of the direction of travelof the saw blade past the work piece, the cut surface of the work piecewill come in contact with a significant area of the sanding surface. Dueto the angular orientation of the sanding surface, material of the workpiece will be gradually sanded away until a flat smooth surfaceangularly oriented with the work piece at a predetermined angle isachieved. Because a significant part of the sanding surfacesimultaneously performs the sanding function, wear will be relativelyuniform.

It is therefore a primary object of the present invention to provide arotary saw blade for cutting and sanding smooth a cut surface made in awork piece.

Another object of the present invention is to provide a rotary saw bladehaving a sanding surface acting relatively uniformly across a cutsurface made in a work piece.

Still another object of the present invention is to provide a rotary sawblade having a shallow cone shaped surface supporting a sanding surface.

Still another object of the present invention is to provide a rotary sawblade for finishing a cut surface of a work piece.

A further object of the present invention is to provide a rotary sawblade for cutting and finishing any angled cut surface made in a workpiece.

A yet further object of the present invention is to provide a rotary sawblade having offset or teeth with a sanding surface to perform a sandingfunction on a cut surface being made.

A still further object of the present invention is to provide a methodfor cutting and finishing a surface of a work piece with a rotary sawblade.

These and other objects of the present invention will become apparent tothose skilled in the art as the description thereof proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described with greater specificity andclarity with reference to the following drawings, in which:

FIG. 1 illustrates a rotary saw blade having a cone shaped sandingsurface for making a finished cut surface in a work piece;

FIG. 2 is a side view illustrating the angular orientation of a rotarysaw blade having a shallow cone shaped surface with respect to a workpiece;

FIG. 3 is a cross sectional view of a shallow cone shaped rotary sawblade having a sanding surface;

FIG. 4 is a cross sectional view of a rotary saw blade having a shallowcone shaped side and a planar obverse side;

FIG. 5 is a partial cross sectional view illustrating the outerperimeter of a sanding surface formed on a rotary saw blade;

FIG. 6 is a partial cross sectional view illustrating the innerperimeter of a sanding surface formed on a rotary saw blade; and

FIG. 7 is a detailed view taken within circle 6 illustrated in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, there is illustrated a conventional work table 10for use in conjunction with a rotary saw blade. The work table includesa slot 12 through which a rotary saw blade extends to perform a cut upona work piece 14. As particularly shown in FIG. 2, work table 10 mayinclude a fence 16 against which work piece 14 is transported past therotary saw blade. Rotary saw blade 20 embodying the present inventionincludes conventional teeth 22 disposed along its perimeter. These teethmay be offset or not, depending upon the type and nature of the cut tobe performed.

The basic structure and configuration of rotary saw blade 20 will bedescribed with joint reference to FIGS. 1, 2 and 3. The rotary saw bladeincludes a generally shallow cone shaped surface 24 defining a coneangle preferably in the range of 1° to 3° off a plane perpendicular tothe axis of rotation of the rotary saw blade. This cone shaped surfacemay be wholly or partially covered by an abrasive material 26 generallydefining a shallow cone shaped disk. The abrasive material may be anapertured disk of sandpaper, abrasive particulates bonded to cone shapedsurface 24, teeth formed in cone shaped surface 24, or the like.

Rotary saw blade 20 may be formed from a circular disk that has beenmade dish shaped by metal forming machinery or machined to size andconfiguration. It includes a central flat roundel 28 with a radiusextending from F to D and an aperture 29 with a radius extending from Fto E. A ring 30 extending radially from D to B may be formed or machinedto a dish shape having a shallow cone defining cone shaped surface 24. Aperipheral radial band 32 extending from radius B to radius A is flatand parallel with a plane defined by roundel 28; band 32 also includesteeth 22. The back side of ring 30 extending radially between C and Bmay be thinned toward the perimeter to provide a concentric surface 34lying in a plane parallel to roundel 28. In its simplest form, rotarysaw blade 20 may be formed from a constant thickness disk havingdiscrete angularly related concentric sections defined by roundel 28,ring 30 and band 32. Such disk can be formed into the shape sought byconventional metal forming techniques. Alternatively, rotary saw blade20 may be formed from a disk blank by machining a shallow cone shapedsurface 24 on one side extending radially from roundel 28, or fromaperture 29, to a point short of the teeth or including the teeth andleaving the obverse side 36 planar, as shown in FIG. 4.

Referring jointly to FIGS. 5, 6 and 7, details of rotary saw blade 20will be described. A shallow radially extending depression 50 is formedin cone shaped surface 24 and defined by outer circular wall 52 andinner circular wall 54. This depression is filled with a composition ofabrasive material 26. Alternatively, an aperture disk of sandpaper orother element having a sanding or finishing function when passed acrossa work piece can be employed. To prevent protruding edge 56 of abrasivematerial 26 from performing a major part of the sanding function due tocontact between the work piece and the protruding edge, the edge shouldnot extend sufficiently to come into contact with the cut surface beingmade in the work piece by the teeth of the saw blade, which cut isrepresented by line 58. That is, the kerf to be cut can be wider thanthe width of band 32 by incorporation offset teeth 22, as illustrated inFIG. 5. Since, it may be easier to form the abrasive material 26 to anessentially constant thickness, there will be a protruding edge 57 ofthe abrasive material adjacent roundel 28. As this part of the abrasivematerial is essentially non-working, protruding edge 57 will have noeffect upon the work piece. It is to be understood that the use ofdepression 50 is not inherently necessary as the abrasive material,whether a composition, sanding disk or the like can be formed directlyupon or attached to surface 24 without a depression.

The operation of saw blade 20 will be described with reference to FIGS.1 and 2. For purposes of the following description, it is assumed thatwork table 10 is a horizontal surface upon which work piece 14 isplaced. A mandrel or arbor 60 penetrably engages aperture 29 andsupports rotary saw blade 20 between a pair of washers 62, 64. Therotary saw blade is secured in place by nut 66 in threaded engagementwith threaded shaft 68 disposed at the end of arbor 60. The axis ofrotation 70 of arbor 60 is offset downwardly vertically from ahorizontal plane 72 by an angle α. The angle α is equivalent to the coneangle of cone shaped surface 24. Thereby, a radial of the cone shapedsurface extending vertically upwardly from the axis of rotation of arbor60 will be perpendicular in three axis to work table 10. This radial isrepresented by line 74, as shown in FIG. 1. As this radial lies in theplane of the finished surface, the finished surface will extendvertically upwardly from the work table, as represented by the 90°angle. The cut made in scrap 18 of work piece 14 is represented by cut76 which is coincident with the corresponding edge of teeth 20 definingline 40, as illustrated in FIG. 2. The angle of cut 76 is off verticalby an amount equivalent to the cone angle of the rotary saw blade andrepresented by 90° minus angle α.

More generally, and irrespective of whether the finished surface is tobe perpendicular to the work table, the following criteria shoulddictate the orientation of the axis of rotation relative to thereference plane defined by the work table. The axis of rotation of therotary saw blade should be oriented to place a radial of the abrasivesurface orthogonal in two (2) axis to the relative direction of travelbetween the rotary saw blade and the work piece. This will define theplane of the finished surface of the work-piece.

As work piece 14 passes to the right, as shown in FIG. 1 in view of thecounterclockwise rotation of saw blade 20, a saw cut 80 will be made toseparate scrap 18 (on the far side of the saw blade). The saw cut in thework piece, as represented by line 58 in FIG. 5, will come into contactwith abrasive material 26 at some point past edge 56 depending upon theamount of lateral offset of teeth 22. The totality of the cut surface ofthe work piece will be abraded, or sanded by abrasive material 26 to avarying depth depending upon the difference in lateral distance betweeneach point on cut line 58 (see FIG. 5) in the work piece and a point online 74 in alignment therewith in a plane parallel to work table 10. Theportion or working area of abrasive material 26 actually performing thesanding function is represented by a section extending upwardly fromwork table 10 and having a rear limit defined by line 74. This sectionis designated by numeral 82 and identified by the parallel lines insteadof by the stippling identifying the remaining surface of the abrasivematerial.

As will be evident to those skilled in the art, a cut surface other thanvertical in work piece 40 can be achieved. A cut at any angle can be setby simply tilting arbor 60 in the vertical plane to the angle desiredfor the cut and then adding a number of degrees to the tilt angleequivalent to angle α.

While the principles of the invention have now been made clear in anillustrative embodiment, there will be immediately obvious to thoseskilled in the art many modifications of structure, arrangement,proportions, elements, materials and components used in the practice ofthe invention which are particularly adapted for specific environmentsand operating requirements without departing from those principles.

We claim:
 1. Apparatus for cutting and finishing a surface of a workpiece, having a longitudinal axis which surface is perpendicular to thelongitudinal axis of the work piece, said apparatus comprising incombination:(a) a rotary saw blade having teeth disposed along itsperimeter for making a cut in the work piece to form the surface on thework piece, said rotary saw including one and an other side and a coneshaped surface defining a shallow cone angle and disposed on the oneside; (b) abrasive material disposed upon the cone shaped surface of theone side for finishing the surface formed on the work piece; and (c) anarbor for supporting said rotary saw blade, said arbor having an axis ofrotation offset from the longitudinal axis of the work piece by the coneangle.
 2. The apparatus as set forth in claim 1 wherein the cone angleis in the range of 1-3 degrees.
 3. Apparatus for cutting and finishing asurface of a work piece which surface is perpendicular to a longitudinalaxis of the work piece, said apparatus comprising in combination:(a) arotary saw blade having teeth disposed along its perimeter for making acut in the work piece to form the surface on the work piece, said rotarysaw including one and an other side and a cone shaped surface defining ashallow cone angle and disposed on the one side, the other side of saidrotary saw blade being planar; (b) abrasive material disposed upon thecone shaped surface of the one side for finishing the surface formed onthe work piece; and (c) an arbor for supporting said rotary saw blade,said arbor having an axis of rotation offset from the longitudinal axisof the work piece by the cone angle.
 4. The apparatus as set forth inclaim 1 wherein the other side of said rotary saw blade includes adepressed cone shaped surface.
 5. The apparatus as set forth in claim 1wherein said teeth are offset.
 6. The apparatus as set forth in claim 1wherein said rotary saw blade includes a central roundel and whereinsaid arbor includes attachment means for securing said roundel to saidarbor.
 7. The apparatus as set forth in claim 1 wherein said rotary sawblade includes an annular band and wherein said teeth are formed in saidband, said band being radially aligned orthogonal to the axis ofrotation of said rotary saw blade.
 8. The apparatus as set forth inclaim 1 wherein said abrasive material defines a concentric banddisposed on said cone shaped surface.
 9. The apparatus as set forth inclaim 1 wherein said abrasive material comprises sandpaper.
 10. Theapparatus as set forth in claim 1 wherein said abrasive materialcomprises a composition of abrasive material adhered to said cone shapedsurface.
 11. Apparatus for cutting and finishing a surface of a workpiece, said apparatus comprising in combination:(a) a rotary saw bladehaving teeth disposed along its perimeter for making a cut in the workpiece to develop the surface of the work piece, said rotary saw bladehaving an aperture at its center and including one side and anotherside; (b) abrasive material for finishing the surface cut in the workpiece by said teeth, said abrasive material being disposed upon the oneside to define a shallow cone shaped surface extending radially inwardlyfor a substantial distance from a location radially inwardly from saidteeth and defining a shallow cone angle with respect to a planeextending radially from the axis of rotation of said saw blade; and (c)an arbor engaging the aperture of said rotary saw blade for supportingsaid rotary saw blade and having an axis of rotation offset fromperpendicular to a plane defined by the other side of said rotary sawblade by the cone angle.
 12. The apparatus as set forth in claim 11wherein the cone angle is in the range of 1-3 degrees.
 13. The apparatusas set forth in claim 11 wherein the other side of said rotary saw bladeis planar.
 14. The apparatus as set forth in claim 11 wherein the otherside of said rotary saw blade includes a depressed cone shaped surface.15. The apparatus as set forth in claim 11 wherein said teeth areoffset.
 16. The apparatus as set forth in claim 11 wherein said rotarysaw blade includes a central roundel and wherein said arbor includesattachment means for securing said roundel to said arbor.
 17. Theapparatus as set forth in claim 11 wherein said rotary saw bladeincludes an annular band and wherein said teeth are formed in said band,said band being radially aligned orthogonal to the axis of rotation ofsaid rotary saw blade.
 18. The apparatus as set forth in claim 11wherein said abrasive material defines a concentric band disposed onsaid cone shaped surface.
 19. The apparatus as set forth in claim 11wherein said abrasive material comprises sandpaper.
 20. The apparatus asset forth in claim 11 wherein said abrasive material comprises acomposition of abrasive material adhered to said cone shaped surface.